Sodium borohydride reduction of propiophenone in presence of mixed sugar/acid media

ABSTRACT

Many chemists have attempted to prepare optically active compounds with chiral reagents, catalyst, and media. Of these investigations, the use of chirally modified metal hydrides to reduce prochiral ketones continues to be studied actively and high enantiomeric excesses of chiral carbinols have been achieved. Among metal hydrides, lithium aluminium hydride modified with chiral alcohols, amino alcohols, and amines has been mainly employed. Recently, attention has been paid however, to the use of sodium borohydricie [NaBH4] in asymmetric reduction. In the present work we would like to report an asymmetric reduction of propiophenone with modified reagents prepared from NaBH4 and d-camphoric acid [IV] in the presence of an optically active sugar derivative in THF solution, for the sake of improving the optical yields of chiral carbinols produced